This invention relates generally to the field of communications and, more specifically, to a system and method for coupling a communication signal to a communication device.
In the world of high-speed communications and networks, there are many types of communications devices, such as digital subscriber line access multiplexers (xe2x80x9cDSLAMsxe2x80x9d), voice switches, and other devices that aggregate subscriber lines into a central office. These communication devices receive signals from subscribers and route them to networks such as ATM networks, IP networks, frame relay networks, or TDM networks. A typical DSLAM has a backplane with connectors on one side to receive signals from a subscriber, and connectors on the other side that accept any number of line cards, which may support any of various xDSL technologies. These line cards are usually housed in a chassis, along with other devices for such things as power modules and switching modules. Because of many various electronic components, circuitry, and other hardware, space is at a premium in central office environments. In addition, because of the many electronic devices and circuitry, considerable electronic interference exists in central office environments, which may cause crosstalk. Therefore, communication device manufacturers strive to manufacture communication devices that maximize space efficiency and minimize crosstalk.
There are different ways to route subscriber signals to line cards. One utilizes a Cisco DSLAM with a 61xx backplane. The Cisco 61xx backplane has Champ connectors connected to one side of the backplane and printed circuit board routing inside the backplane for routing the signals to the appropriate line cards on the other side of the backplane. The routing inside the backplane usually consists of many traces within the backplane, which causes the backplane to have greater thickness and greater surface area. The routing also results in impedance discontinuities and crosstalk. There are also large voids in the backplane ground planes to accommodate TNV to SELV safety requirements for the Champ connectors and the line card connectors. These voids allow increased ElectroMagnetic Interference (xe2x80x9cEMIxe2x80x9d).
Another way of routing subscriber signals to line cards is utilized in a Lucent(copyright) Stinger(trademark). The Lucent(copyright) Stinger(trademark) is a digital subscriber line access concentrator that utilizes a midplane design, which eliminates routing requirements in the midplane for the incoming telco signals. However, the Stinger(trademark) does have routing on line protection modules on one side of the midplane. The line protection module has Champ connectors that receive the subscriber signals, and routing that routes the signals to connectors that connect to the midplane connector on one side of the midplane. The pins of this connector pass through the midplane and become the receiving connector for the line cards. Line cards on the other side of the midplane receive the signals via these connectors. Therefore, the signals are not directly sent to the line card without routing. Also, the midplane design requires physical access to both sides of the chassis for installation and maintenance.
An additional method of coupling subscriber signals to line cards utilizes no backplane and no line protection modules with routing. This method uses insulation displacement connectors with flexible wires connected thereto. These flexible wires are then connected to insulation displacement connectors that connect to a line card. Even though there is a direct connection to the line card with no routing requirements, the flexible wires still waste space, and cause electronic interference. In addition, the termination of the wires at the insulation displacement connectors increase manufacturing difficulty and labor cost, and decreases reliability.
The challenges in the field of communications continue to increase with demands for more and better techniques having greater flexibility and adaptability. Therefore, a need has arisen for a new system and method for coupling a communication signal to a communication device.
In accordance with the present invention, a system and method for coupling a communication signal to a communication device is provided that addresses disadvantages and problems associated with previously developed systems and methods.
According to one embodiment of the invention, a system for coupling a communication signal to a communication device includes a backplane, having first and second sides, and a connector, adapted to receive the communication signal, coupled to the backplane on the first side. The connector has a first set of conductive pins that extend through the first side of the backplane and protrude out the second side of the backplane. A portion of the first set of conductive pins is adapted to receive a line card connector formed with a plurality of contact cavities. The system further includes a guide member operable to guide a line card into the line card connector.
According to another embodiment of the invention, a method for coupling a communication signal to a communication device includes coupling a connector having a first set of conductive pins to a backplane having first and second sides. The connector is adapted to receive the communication signal. The method further includes protruding the first set of conductive pins out the second side of the backplane, wherein a portion of the first set of conductive pins is adapted to receive a line card connector formed with a plurality of contact cavities. The method also includes positioning a housing adjacent the first set of conductive pins.
Embodiments of the invention provide numerous technical advantages. For example, a technical advantage of one embodiment of the present invention is that wasted backplane real estate is substantially reduced. This real estate savings is accomplished by placing the Champ connector near the line card centerline. There are no routing requirements for the communication signals from the Champ connectors to the line cards. Thus, the backplane is reduced in area and thickness, thereby saving valuable space. In addition, impedance discontinuities and crosstalk are minimized because of less metallization in the backplane. Another technical advantage of one embodiment of the present invention is that a printed circuit board berrol is not required if the connector pins are designed to press directly into fiberglass or the pins on the Champ connector could pass through the backplane and be held in place by the shroud. Another technical advantage of one embodiment of the present invention is that overmolding connector pins as they pass through a backplane reduces the safety requirements between the telco pins and chassis ground from a creepage distance to a distance through insulation. This overmolding allows a ground fill to extend between the pins, thereby reducing the EMI aperture from a large void to many small holes.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.